Nanoparticles can be used as delivery vehicles for therapeutic and imaging agents with improved biodistribution and increased delivery efficiency to solid tumors. In particular, nanomedicine's greatest advantage over conventional therapies is its ability to combine more than one function by enabling the design of multifunctional nanoparticles that target, image, and destroy tumors. This has led to the development of various nanoparticle delivery systems such as liposomes, dendrimers, other lipidic and polymeric nanoparticles, and metal nanoparticles (e.g., iron oxide and gold). While the shape of the majority of these particles is spherical due to the methods of preparation, recent advances have fabricated oblate- and rod-shaped nanostructures suitable for biomedical applications, such as gold nanorods, nanoworms, and nanonecklaces. For example, the so-called nanoworms consist of iron oxide cores aligned along strands of high-molecular weight dextran. A nanonecklace was formed by attaching monofunctionalized gold nanoparticles onto polylysine.